[PATCH] x86: Use more __sync builtins in atomic-machine.h

[Wilco Dijkstra]

Hi Adhemerval/Uros,

I've resent my old patch [1] with some updates [2]. This removes all
useless atomic macros from generic code - but not yet those in machine
specific headers. I have some other outstanding patches that deal with
the fences.

[1] https://sourceware.org/pipermail/libc-alpha/2022-October/142645.html
[2] https://sourceware.org/pipermail/libc-alpha/2025-September/169698.html

Cheers,
Wilco